An employee is allowed to leave company premises during meal breaks

Dear PAO,

My uncle works as a company doctor in a manufacturing company, with his shift running from 8 a.m. to 5 p.m., including a regular meal break from 12 p.m. to 1 p.m. His residence is just a three-minute drive away from his workplace. Last Tuesday, he left the clinic around noon to have lunch at his residence. A few minutes later, the clinic received an emergency call from the company's assembly department when one of its workers had suffered a heart attack. The patient arrived at the clinic at 12:25 p.m. The nurse on duty immediately rushed him to the hospital. When my uncle reached the clinic around 12:30 p.m., the nurse on duty had already left with the patient. The patient died the next day. Following an internal investigation, the company deemed my uncle's explanation unacceptable and the management charged him with abandonment of post while on duty. May I know if my uncle can be disciplined for abandonment?